Yellow Ones Research Articles

Assessment of color response and activity rhythms of the invasive black planthopper Ricania speculum (Walker, 1851) using sticky traps

To be effective, management strategies of invasive alien species cannot ignore their spatiotemporal behavior particularly those exerting serious damages to human activities. The black planthopper Ricania speculum is an Asian insect that has been reported as an alien invasive species in Italy, where it threatens local plant diversity, including important crops. In our work, we analyzed the activity rhythms of this species through circular statistics and the efficiency of chromotropic traps to capture adult individuals. Captures were carried out in central Italy, where the black planthopper is showing a remarkable range expansion, after its first discovery in 2009. We observed that the species was mainly crepuscular, with a high intersexual activity overlap. Activity rhythms changed between July-August and September-October, with changing heliophany, but peaked at sunset and were the lowest in the second half of the night and early morning. The insects were mostly caught by green traps, particularly in September, which is the period of egg-laying inside the leaves; conversely, orange ones were avoided, and yellow ones captured proportionally to their local availability. Strategies for controlling this species should consider concentrating trapping effort during the activity peak, using green sticky traps to enhance the capture success of each trap, with the lowest impact over non-target species.

Rare earth element bioaccumulation in the yellow and silver European eel (Anguilla anguilla): A case study in the Loire estuary (France)

In the present work, rare earth elements (REEs) were measured in European eel muscles (Anguilla anguilla) from the Loire estuary in France. This study site is characterized by a large anthropogenic pressure with potential activities releasing REEs such as oil refineries, aeronautic and naval industries, wind turbine industries, hospitals with magnetic resonance imaging and coal-fired power plants. These activities may lead to increased REE concentrations in sediments the primary habitat of European eels. In the present work, REE bioaccumulation was evaluated by determining the concentrations in yellow and silver eel muscles sampled at three different locations in the Loire estuary and at two periods (2011/2012 and 2018/2019). The aims of this study were the understanding of the spatio-temporal influences (sampling site and sampling period) and intraspecific variations (age, sex, sexual maturation, length, weight, and parasitism) on the whole REE bioaccumulation. The mean value of the sum of REE concentrations (∑REEs) was 2.91, 6.48 and 12.60 µg/kg of muscle from respectively yellow eels, female silver eels and male silver eels fished in 2018/2019. The results showed that silver males accumulated more REEs than silver females and silver eels accumulate more REEs than yellow ones. Regarding the determination of spatio-temporal variations, an increase of REE concentrations for silver eel muscles between the two periods was observed, certainly related to the increase of REE uses. Finally, a trend of higher contamination of eels sampled in the downstream of Nantes was noticed for yellow eels.

СЕЗОННА ДИНАМІКА ВМІСТУ ФОТОСИНТЕТИЧНИХ ПІГМЕНТІВ У СТРОКАТОЛИСТИХ ФОРМ BERBERIS THUNBERGII DC.

The work deals with the peculiarities of seasonal dynamics of the content of photosynthetic pigments in leaves and their parts with various colouring in variegated-leaf forms of Berberis thunbergii DC.
 Three forms were studied: green-leaf, purple-leaf 'Harlequin', and form 'Coronita', which has three colour patterns of leaves and their different parts (peripheral and central) with substantial differences in colouring. The photosynthetic pigments were extracted from leaves and their parts using dimethyl sulphoxide; in given extracts, the quantity of these pigments was measured by spectrophotometer SF-2000.
 We determined general and specific peculiarities of the content of chlorophyll and carotenoids in the leaves of one- and two-year-old shoots of three forms of B. thunbergii during growth and heterogeneity of their quantity in differently coloured parts of the leaf blade of 'Coronita'. In the yellow margins of pink-coloured leaves of one-year-old shoots of “Coronita”, the content of green and yellow pigment was usually lower than in the peripheral part of purple-coloured leaves. The maximum content of both types of photosynthetic pigments in this part of leaves of one- and two-year-old shoots was noted in the first half of the growing season. The same applies to the middle parts of the pink- and purple-coloured leaves; the lowest content of the pigments is typical of hot and dry months. The yellow-green- and brown-coloured leaves of form 'Coronita' differ from the other two leaf types in that the content of chlorophyll and carotenoids is at the highest in the second half of the growing season, and it is significantly higher. The ratio of chlorophyll a/chlorophyll b in the leaves of three forms recorded in September-October increases in comparison with such ratio in May-July. It shows that, at the end of the growing season, catabolism of chlorophyll b takes place faster than one of chlorophyll a. With regard to the ratio chlorophyll/sum of carotenoids, this index decreases in autumn in comparison with the first half of the growing season; it shows that green pigments have more active catabolism than yellow ones.
 The maximum content of chlorophyll in the leaves of B. thunbergii is generally recorded in the first half of the growing season; this index decreases in the hot and dry second half, but when the heat drops, the quantity of carotenoids increases slightly. In this regard, variegated-leavf form 'Coronita' stands out; it is characterized by high endogenic variability in the content of pigments within leaf blades depending on the colouring of different parts of a leaf.

Biochemical Characterisation and Sensory Evaluation of Differently Coloured and Shaped Tomato Cultivars

Antioxidant capacity, total phenolic content, colour, sugar, volatiles, ascorbic acid and carotenoid (β-carotene and lycopene) contents of differently coloured and shaped tomato cultivars (cvs) grown in the Eastern Mediterranean region, Turkey were determined, along with a sensory evaluation. Tomato cultivars of two different types (cherry and beefsteak) and four different colours (red, yellow, orange and brown) were analysed. All plants were simultaneously grown in the same field and subjected to identical horticultural practices to minimise the effects of environmental conditions and to maximise those related to genotype. The red cherry cultivar had the highest lycopene content, while the orange beefsteak cultivar had the highest β-carotene content. The highest antioxidant capacity, total phenolic content and hardness scores were found in cherry-type tomatoes, except the yellow one. The red cherry cultivar had the highest sugar content. Red and brown cherry cultivars were also significant in terms of their high carotenoid and sugar contents, along with a high antioxidant activity. The brown cherry cultivar had the highest total phenol content. The highest quantities of 2-hexenal, 3-hexen-1-ol, and 6-methyl-5-hepten-2-one were detected in red cultivars. The brown cherry cultivar had the highest sweetness, typical aroma and hardness scores, while the yellow beefsteak cultivars the lowest sweetness typical aroma scores. In terms of sensory parameters, red and brown cultivars scored higher than yellow and orange ones.
 
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 In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 3, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue.
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Opuntia ficus-indica (L.) Mill. fruit as source of betalains with antioxidant, cytoprotective, and anti-angiogenic properties.

The aim of this work was to investigate the phytochemical profile and biological properties of different colours of betalain cactus pear extracts, evaluating their antioxidant, cytoprotective, and anti-angiogenic properties by cell-free, cell-based, and in vivo assays. A QuEChERS extraction method followed by RP-LC-DAD-MS/MS analysis showed that indicaxanthin and betanin were the main compounds (≥94.32% and ≥96.95%, respectively). Orange cactus pear extracts exert the best antioxidant activity in all assays carried out, in particular into ORAC (17,352.55±987.407mg trolox equivalents/100g dry weight) and β-carotene bleaching (60.35%) assays. The red ones, instead, showed the best cytoprotective activity decreasing the cell mortality, LDH, and Caspase-3 release ranging from 4.0 to 55%. According to antioxidant results, the orange cactus pear extracts showing also the highest anti-angiogenic activity (IC50 19.31μg/ml), followed by the red (IC50 23.55μg/ml) and the yellow ones (IC50 33.97μg/ml). In light of the results and correlation analysis, the behaviour of these molecules varies a lot according to their structure and physicochemical features and synergistic activity between betalain classes may be postulated; so the plant complex could be of greater interest compared with the isolated molecules for potential nutraceutical and pharmaceutical uses.

Effects of Varying the Color, Aroma, Bitter, and Sweet Levels of a Grapefruit-Like Model Beverage on the Sensory Properties and Liking of the Consumer.

Color, aroma, sweet, and bitter tastes contribute to the sensory perception of grapefruit juice. Consumers differ about liking grapefruit. A reason is the bitter taste that characterize the fruit. The objective was to determine the effect of varying the color (red or yellow), aroma (two levels), bitterness (three levels), and sweetness (three levels) of a grapefruit-like model beverage, on consumers’ liking and perception of its sensory properties. The sensory profiles of thirty-six grapefruit-like beverages, created on the basis of a factorial design, has been described. Consumers rated their liking of color, aroma, and flavor of the twelve most diverse beverages. Bitter and sweet levels of the beverages had a significant effect on the flavor and aftertaste attributes. Aroma concentration had a significant effect on the majority of the sensory attributes. Color had a significant effect on perception of some of the aroma attributes, as well as the grapefruit’s flavor intensity. Consumers liked the red beverages more than the yellow ones, and those with low aroma over the high aroma intensity. Consumers preferred the low bitter/high sweet beverages. Pungent and grapefruit aroma were found to be negative drivers for liking of the aroma. Sweet and citrus flavors were found to be positive drivers and sour and bitter flavors were found to be negative drivers of flavor-preferences (or liking) of the tested beverages.

Investigation on Modulation Speed of Photon-Recycling White Light-Emitting Diodes With Vertical-Conduction Structure

The speed performance of a high lumen and high color rendering index (CRI) gallium nitride-based white-light light-emitting diode (LED) has been investigated in detail by measuring its electrical-to-optical frequency responses with different color filters at the receiver end. The ultra-violet/blue/green multiple quantum wells (MQWs) are stacked in the studied LED chips, which have a vertical conducting structure and red phosphor coating for generating white light with high CRI. The typical studied LED exhibits a smaller 3 dB bandwidth (0.6 MHz versus 2 MHz) compared with a reference LED with ultra-violet/blue MQWs and a yellow phosphor coating. This finding suggests that the fluorescent decay time of red phosphor is much longer than that of yellow ones (approximately 270 ns versus approximately 80 ns). In addition, the extracted carrier lifetime inside blue/green InxGa1-xN/GaN MQWs under UV light pumping/modulation is as long as approximately 50 ns, which is much slower than that of forward-biased current modulation (approximately 50 ns versus on–off keying modulation scheme are demonstrated under a moderate operation bias current (approximately 0.75 A) of studied LEDs.

Carotenoid profile and basic structural indicators of native Peruvian chili peppers

The cognition of original qualitative attributes of native Peruvian chili peppers elucidate their potential industrial exploitation. There is a lack of scientific information about chili pepper physicochemical and nutritional attributes, that hampers their immediate industrial use. Therefore, the aim of the present study was to characterize twenty Peruvian chili pepper landraces in terms of structural and nutritional properties. In particular, the Bostwick consistency index of chili purees, dry matter, dietary fibers and pectin content were determined. In addition, the color and carotenoid profile of each landrace were studied. A wide range of consistency and stability were found, and partially explained by the dry matter, dietary fiber and pectin content. C. annuum landraces displayed the highest dry matter and fiber content. Moreover, different carotenoid profiles were observed, being β-carotene the most abundant in almost all the samples. Capsanthin was present only in red landraces, while yellow ones had low total carotenoid content. High Retinol Activity Equivalent levels were determined for red peppers, while high insoluble dietary fiber level was found in all the samples. Cluster analysis, including all the chili pepper attributes, showed no relation between taxonomical classification and chili peppers structural, sensorial, and nutritional characteristics. Unique features of studied chili pepper landraces presented in this work should be considered during their industrial processing. In this context, these results might be considered a starting point for processing design and for the proper valorization of this raw material.

Reversible Band Gap Narrowing of Sn-Based Hybrid Perovskite Single Crystal with Excellent Phase Stability.

An intriguing reversible band gap narrowing behavior of the lead-free hybrid perovskite single crystal DMASnI3 (DMA=CH3 NH2 CH3 + ) from yellow to black is observed without phase transformation. We discuss the transformation mechanism in detail. More interestingly, the transformed samples in black can rapidly self-heal into yellow ones when exposed to deionized water (DI water). Contrary to other hybrid perovskites, DMASnI3 crystals exhibit excellent water phase stability. For example, DMASnI3 was immersed in DI water for 16 h and no decomposition was observed. Inspired by its excellent water phase stability, we demonstrate a potential eco-friendly application of DMASnI3 in photo-catalysis for H2 evolution in DI water. We present the first H2 evolution rate of 0.64 μmol h-1 with good recycling properties for pure DMASnI3 crystals. After the narrowing process, the optical band gap of DMASnI3 can be lowered from 2.48 eV to 1.32 eV. Systematical characterizations are applied to investigate their structures and optoelectronic properties. The reversible band gap narrowing behavior and outstanding electrical properties, such as higher carrier mobility and long carrier lifetime show that DMASnI3 has a great potential for optoelectronic applications.

Reversible Band Gap Narrowing of Sn‐Based Hybrid Perovskite Single Crystal with Excellent Phase Stability

AbstractAn intriguing reversible band gap narrowing behavior of the lead‐free hybrid perovskite single crystal DMASnI3(DMA=CH3NH2CH3+) from yellow to black is observed without phase transformation. We discuss the transformation mechanism in detail. More interestingly, the transformed samples in black can rapidly self‐heal into yellow ones when exposed to deionized water (DI water). Contrary to other hybrid perovskites, DMASnI3crystals exhibit excellent water phase stability. For example, DMASnI3was immersed in DI water for 16 h and no decomposition was observed. Inspired by its excellent water phase stability, we demonstrate a potential eco‐friendly application of DMASnI3in photo‐catalysis for H2evolution in DI water. We present the first H2evolution rate of 0.64 μmol h−1with good recycling properties for pure DMASnI3crystals. After the narrowing process, the optical band gap of DMASnI3can be lowered from 2.48 eV to 1.32 eV. Systematical characterizations are applied to investigate their structures and optoelectronic properties. The reversible band gap narrowing behavior and outstanding electrical properties, such as higher carrier mobility and long carrier lifetime show that DMASnI3has a great potential for optoelectronic applications.

Consumer expectations for vegetables with typical and atypical colors: The case of carrots

The variety of fruits and vegetables in today’s supermarkets is enormous. We investigated how color may lead consumers to anticipate differences in product properties. Forty volunteers rated the expected properties for carrots with different colors presented in pictures, together with their familiarity, purchase intention, and intended preparation method on 7-point scales. We found most positive expectations for the typical and most familiar kinds of orange carrots. Lower saturation of orange was associated with lower attractiveness and freshness, whereas higher orange saturation was evaluated as more artificial. Brown spots on carrots were associated with disease and such carrots were regarded less healthy. Carrots in atypical colors were rated as less familiar, attractive and healthy than orange ones. In comparison with the orange carrots, red carrots were expected to taste sourer and spicier, purple and yellow carrots were rated less nutritious and more artificial, with purple carrots expected to taste more bitter and yellow ones more sour. White and white-green carrots rated lower on sweet, and higher on sour, bitter, and spicy. These carrots were considered less ripe and less nutritious than orange ones. These results indicate that color hue and saturation have substantial impact on consumers’ expectations about sensory and functional properties, including freshness and nutritional value. Some of these expectations may be derived from associations to other vegetables, as reflected by high ratings for spiciness (red pepper) and taste intensity (turnip, radish). However, low attractiveness ratings also suggest that consumers may be reluctant to try unfamiliar variants, at least at first glance. Although atypical colors produce culinary opportunities, commercial success may be limited until consumers integrate them in their everyday habits.

Changes in nutraceutical quality in tomato under different organics substrates and shade net conditions

ABSTRACT The yield and nutraceutical quality of tomato under shade net was evaluated, using different mixtures of organic fertilizers at Torreon, Coahuila in northern Mexico. The treatments consisted of mixtures using sand (S), vermicompost (VC), solarized bovine manure (SB), agricultural soil (AS) and mineralized compost (MC). The treatments were: T1 (SVC/80:20), T2 (SSB/80:20), T4 (SVCAS/80:15:05), T5 (SMC/80:20), T6 (SSBAS/80:15:05), and a control treatment T3 (S/100) with Steiner solution. The results showed that in yield, the best organic treatment was T1 with 3.18 kg plant-1; while the highest yield was the control with 3.58 kg plant-1. Phenolic content in the organic treatment fruits was 36.0 to 56.94 mg equivalent of Gallic Acid per 100 g in fresh weight for T1 and T5, respectively. The greatest antioxidant capacity was obtained in T4, with 445 μM equivalent in Trolox/100 g fresh weight. The lycopene content in the tomato fruits was, in average, 32% higher in the red fruits than in the yellow ones, with 3.12 and 2.24 mg lycopene values·100 g·pulp-1, respectively. In red fruits, the T5 treatment presented the highest value and in the yellow ones, T1 was the highest, with 3.52 and 2.35 mg lycopene values·100 g·pulp-1, respectively. Keywords: Solanum lycopersicum L, DPPH, phenols, lycopene.

Non-invasive study of natural dyes on historical textiles from the collection of Michelangelo Guggenheim

A selection of historical textile fragments from the Venetian art dealer Moisè Michelangelo Guggenheim collection, ranging from XV to XVIII century, has been investigated by means of non-invasive techniques in order to reveal the coloring materials. Imaging was preliminarily used to visually investigate the selected artwork fragments in order to investigate their structure and conservation conditions; Fiber Optics Reflectance Spectroscopy (FORS) allowed recognizing the main natural dyestuffs, such as indigotin and anthraquinones-based compounds, except the yellow ones, difficultly identifiable when using this non-invasive technique. Collected spectroscopic data have been also elaborated by using a clustering algorithm that permitted to group collected spectra on the basis of similar properties and evidencing their inflection point wavelength as the most influencing feature.

A non-invasive spectroscopic study to evaluate both technological features and conservation state of two types of ancient Roman coloured bricks

The study of both original and decaying compounds is relevant in understanding the chemistry behind the deterioration processes, above all in open museum contexts where environmental stressors affect the artefacts. In this sense, a combination of non-invasive spectroscopy techniques (Raman spectroscopy, μ-X-ray fluorescence and X-ray diffraction) was applied on an ancient Roman building (130 CE), the “Casa di Diana” Mithraeum at Ostia Antica archaeological site. The aim is to study the raw materials, manufacturing and decaying products of the two observed types of Roman fired bricks (red and yellow) that compose the building.The present study estimates an illite raw material of carbonate-bearing marine clay likely referring to the common deposits of central/southern Italy, which contain calcite as accessory phase and a-plastic fraction constituted by quartz, feldspar and opaques. This clay material was added with volcanic temper characterised by abundant clinopyroxene and analcime (from analcimization of leucite) that are typical of the Roman Province volcanism. The firing would be probably the result of oxidizing conditions, as proved by the hematite presence. Thanks to the existence of specific neoformed mineral phases during firing it was possible to assess different temperatures ranges. In detail, the red/orange bricks, for the existence of gehlenite (formed from calcite and its reaction with silicates), were fired at 800–900 °C range; whereas, the yellow ones are characterised by the lack of gehlenite and the disappearance of illite/muscovite, which indicates firing temperature at over 900 °C.Regarding the decaying products, the gypsum covers most of the surface of most bricks, both red and the yellow ones, but these latter are more susceptible to environmental stressors (sulphates and carbonates).Therefore, this work points out how by integrated non-invasive approaches it is possible trace back to original firing temperature, technology of manufacture, interpreting ceramic data.

Changes in nutraceutical quality of tomato under different organic substrates

ABSTRACT Yield and nutraceutical quality of Sahel tomato cultivar under shade net was evaluated using different mixtures of organic substrates in Coahuila, northern Mexico. The treatments consisted of mixtures using sand (S), vermicompost (VC), solarized bovine manure (SB), agricultural soil (AS) and mineralized compost (MC). The treatments were: T1 (S:VC, 80:20), T2 (S:SB, 80:20), T3 (S:SB:AS, 80:15:05), T4 (S:VC:AS, 80:15:05), T5 (S:MC, 80:20), and a control treatment T6 (S, 100%) with Steiner solution. Yield results showed that the best organic treatments were T5 and T4 with 3.48 and 3.33 kg plant-1, respectively; while the highest yield was in control (T6) with 3.71 kg plant-1. The highest phenolic content in the organic treatment of fruits was 56.94 mg equivalent of gallic acid per 100 g in fresh weight for T5, while the treatment with chemical fertilization obtained 49.82. The greatest antioxidant capacity was obtained in T4, with 478.34 μM equivalent of Trolox/100 g fresh weight. Two colors were evaluated (yellow and red) corresponding to two ripeness phases. Lycopene content in tomatoes was in average 32% higher in the red colored fruits than in the yellow ones, with 3.12 and 2.24 mg lycopene 100 g pulp-1 values, respectively. For the red ones, treatment T5 showed the highest value (3.52) and in yellow ones T1 reported 2.35, while T2 presented the lowest values for both colors. Organic fertilizers based on S:VC can induce good amounts of lycopene in fruits of both colors, as well as improve phenols and antiOX.

JUICES OF PRICKLY PEAR FRUITS (OPUNTIA SPP.) AS FUNCTIONAL FOODS

The prickly pear, (Opuntia spp.) is consumed mainly as fresh fruit. We characterized and quantified secondary metabolites, their antioxidant capacity in vitro in juice of ten Opuntia spp. variants. Gallic acid was abundant in most variants. Catechin and epicatechin isomers, and procyanidins B1 and B2 were present in most variants. Ascorbic acid content was higher than 84 mg. Betacyanins stand out in red-colored juices, betaxanthins in the yellow ones; this caused lack of relationship between antioxidant capacity and total phenolic content. The content of soluble fiber, sugars, betalains and ascorbic acid content position this juice as a functional food.

Crecimiento inicial de Eugenia stipitata, Inga spectabilis e Inga edulis en Napo, Ecuador

Agriculture has been one of the causes of deforestation, causing environmental impact and soil degeneration, which leads to lower income earned by farmers; hence the need to implement agroforestry systems .This research aims to describe fromthe initial growth of Eugenia stipitata, Inga edulis, and Inga spectabilis to 320 days after emergence. The study took place at the Amazon Research and Conservation Center of the Amazonas State University, during 2014 and 2015. The growth process was evaluated in regards to plant height, stem diameter, number of leaves, and branch length. Plant height and stem diameter were compared over time applying variance analysis. Precipitation was also compared to analyze whether its variations had a direct influence on plant growth. The linear and polynomial models fitted better for thespecies regarding plant height and sprout diameter. Predominance of green leaves compared to yellow and dry ones, as branch length showed significant differences over all the sampling periods. The two-way analysis of variance showed significant differences in the correlation between age and precipitation over plant height and stem diameter. The outcomes led to conclude that Eugenia stipitata had a lower growth than both Inga edulis and Inga spectabilis. Branch production and growth and the number of leaves were also important elements of the growth process.

High innate attractiveness to black targets in the blue blowfly, Calliphora vomitoria (L.) (Diptera: Calliphoridae)

Calliphora vomitoria is a myiasis-causing fly in many animal species including humans. The control of blowflies is still anchored on the use of chemicals. However, mass trapping and lure-and-kill techniques represent a promising alternative to pesticides. Visual and olfactory cues are the main stimuli routing the fly’s landing behavior. Notably, color attractiveness has been barely explored in flies of medical and veterinary importance, with special reference to blowflies. In this study, we investigated the innate color preferences in C. vomitoria adults, testing binary combinations of painted targets under laboratory conditions. The identity of tested species C. vomitoria was confirmed by DNA sequencing (18S and cox1 genes). C. vomitoria flies showed a significant preference for black colored targets in all tested binary color combinations, after 5, 15, 30 and 60 min of exposure. Black targets were significantly preferred over blue, red, yellow and white ones. Spectral characteristics of all tested color combinations were quantified and the innate attraction of blowflies towards black targets was discussed in relation to their behavioral ecology. To the best of our knowledge, this is the first report on innate color preferences in the Calliphora genus. Our findings can be useful to develop new, cheap and reliable monitoring traps as well as “lure and kill” tools to control blowfly pests.

Phenotypic and Genetic Diversity of the Culinary-Medicinal Winter Mushroom Flammulina velutipes (Agaricomycetes) in China.

Flammulina velutipes is one of the mushrooms produced most widely in East Asia. In this study we investigated phenotypic variations of 7 agronomic traits in 37 F. velutipes strains from China, and we analyzed their genetic diversity with 70 simple sequence repeat markers. The Shannon information index and gene diversity were 0.894 and 0.478, respectively, demonstrating high genetic variation among the tested strains. Poor genetic variation was found among white strains, in contrast to yellow ones. Analysis of population structure resolved 2 unambiguous genetic groups in the tested F. velutipes strains, with little differentiation between them (FST = 0.016). Yellow cultivars possibly originated from indigenous wild strains in southwest China. Phenotypic correlations were identified among the 7 traits. In particular, stipe length (SL) was significantly positively correlated with yield, indicating that SL could be used as an index for breeding high-yield strains. The 2 genetic groups, and white strains and yellow ones, showed significant differences between SL, yield, and the time interval (days) from mycelial scratch to formation of the first fruiting body. These results indicate that these 3 traits were stratified by population structure. Detection of genetic and phenotypic variations would lay the groundwork for further breeding of elite F. velutipes strains.

The yellow specialist: dronefly Eristalis tenax prefers different yellow colours for landing and proboscis extension.

Droneflies, imagoes of the hoverfly Eristalis tenax, are known to possess a preference for yellow flowers, i.e. they prefer to visit yellow flowers and prefer to extend the proboscis to yellow colours. In this study we disentangle these colour preferences by investigating the landing reaction and proboscis reflex with particular reference to intensity, spectral purity and dominant wavelength of colour stimuli and their UV reflection properties. In multiple-choice tests, naïve and non-trained flies prefer to land on yellow colours independent of their UV reflection characteristics, but also accept blue, white and pink colours if they absorb UV and are of sufficient brightness. Flies trained to land on colours other than yellow still prefer yellow colours to some extent. Moreover, the flies prefer bright over dark yellow colours even if trained to dark yellow ones. The flies refuse to land on dark colours of all hues. Naïve flies exhibit the proboscis reflex only to pure yellow pollen. These experiments show for the first time that landing in droneflies is triggered by a yellow colour independent of its UV reflection properties, but proboscis extension is triggered by yellow colours strongly absorbing blue and UV. The ability to discriminate colours is better than predicted by the categorical colour vision model. The colour preferences in E. tenax represent a fine-tuned ability to visit yellow flowers displaying a UV bull's-eye pattern.